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A296613 Smallest k such that either k >= n and k is a power of 2, or k >= 5n/3 and the prime divisors of k are precisely 2 and 5. 1
1, 2, 4, 4, 8, 8, 8, 8, 16, 16, 16, 16, 16, 16, 16, 16, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 128, 128 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

First disagreement with A062383(n-1) is at n = 129.

For n > 2, a(n) is not squarefree. - Iain Fox, Dec 17 2017

LINKS

Eric M. Schmidt, Table of n, a(n) for n = 1..10000

Bernadette Faye, Florian Luca, Pieter Moree, On the discriminator of Lucas sequences, arXiv:1708.03563 [math.NT], 2017, Theorem 1.

PROG

(PARI) a(n) = for(k=n, +oo, if(k == 2^valuation(k, 2) || (k >= 5*n/3 && factor(k)[, 1] == [2, 5]~), return(k))) \\ Iain Fox, Dec 17 2017

CROSSREFS

Cf. A033846.

Sequence in context: A265544 A290221 A098820 * A062383 A034583 A076347

Adjacent sequences:  A296610 A296611 A296612 * A296614 A296615 A296616

KEYWORD

nonn

AUTHOR

Eric M. Schmidt, Dec 16 2017

STATUS

approved

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Last modified August 13 19:30 EDT 2020. Contains 336451 sequences. (Running on oeis4.)